Thermo flask



FIG. 1 is an oblique perspective view of the thermo flask;

FIG. 2 is a right side view of the thermo flask, as shown in FIG. 1;

FIG. 3 is a left side view of the thermo flask;

FIG. 4 is a front side view of the thermo flask;

FIG. 5 is a back side view of the thermo flask;

FIG. 6 is a top view of the thermo flask; and,

FIG. 7 is a bottom view of the thermo flask. 

The ornamental design for a thermo flask, as shown and described. 